Field of the Disclosure
The present disclosure relates to apparatus, systems, and methods for providing wear leveling in solid state devices.
Related Disclosure
Flash memory can include an improved form of Electrically-Erasable Programmable Read-Only Memory (EEPROM). Traditional EEPROM devices are only capable of erasing or writing one memory location (e.g., a memory cell) at a time. In contrast, flash memory allows multiple memory locations to be erased or written in one programming operation. Flash memory can thus operate at a higher speed compared to traditional EEPROM.
Flash memory, which can also be referred to as a flash memory device or a flash storage device, has a number of advantages over other storage devices. It generally offers faster read access times and better shock resistance than a hard disk drive (HDD). Unlike dynamic random access memory (DRAM), flash memory is non-volatile, meaning that data stored in flash memory is not lost when power to the memory is removed. These advantages, and others, may explain the increasing popularity of flash memory for storage applications in devices such as memory cards, USB flash drives, mobile phones, digital cameras, mass storage devices, MP3 players and the like.
Current flash storage devices suffer from a number of limitations. Although a flash memory device can be read or written at the physical page level, it can only be erased or rewritten at the block level, which includes multiple physical pages. For example, beginning with a pre-erased block, data can be written to any physical page within that block. However, once data has been written to a physical page, the contents of that physical page cannot be changed or removed until the entire block containing that physical page is erased. In other words, while flash memory can support random-access read and write operations, it cannot support random-access rewrite or erase operations.